RETINOBLASTOMA- LIGHT AND LIFE
Retinoblastoma is an eye cancer that arises inside the eye, from a layer called the retina. Retinoblastoma most commonly affects young children under the age of five years. This rare disease is the most common form of cancer affecting the eye. The cancer could affect one or both eyes. This cancer is the most curable form of cancer that affects children, with 95% complete cure, especially if they are detected early and treated appropriately. Early diagnosis and proper treatment can save the child, save the eye and save vision. The tumor is always fatal if detected too late or treatment not provided.
Retinoblastoma is the third most common cancer in a child, occurring one in twenty thousand births. Currently, we estimate about 1500 children to have retinoblastoma every year in India out of the 8000 cases estimated worldwide. Due to the lack of awareness and the lack of access to appropriate treatment, the cancer is unfortunately detected at an advanced stage. The current success rate for treatment is about 50% to 90% and could be much better.
The signs of retinoblastoma include:
- Common Signs
White Reflex: The center part of the eyeball is called the pupil, which is normally “black” in color. In a child with retinoblastoma, the pupil might appear white, especially when a light shines on the eye in a dim room.
Squint Eyes: Also known as “crossed eyes”. Any misalignment of the eye in a young child may be the first sign of retinoblastoma.
Rare Signs
Decreased Vision: The child’s vision may worsen as a result of retinoblastoma. The infant may not track moving objects as well as before.
Bleeding in the Eye: This is caused when blood leaks into the eye, and either forms a layer of blood in front of the pupil or a clot of blood behind the lens.
Advanced Retinoblastoma: This can present with a red, painful or swollen eye, or even a shrunken eye – which could be hiding a cancer inside.
Retinoblastoma is diagnosed by a doctor who specializes in the disease. It is diagnosed clinically by an experienced specialist. Other forms of the eye tests that aids in diagnosis includes ultrasound, magnetic resonance imaging (MRI) and rarely computerized tomography (CT). CT is best avoided especially in cases affecting both eyes.
The treatment of retinoblastoma is very successful if it is diagnosed and treated early. One way to get rid of this cancer is to completely remove the affected eye. This treatment is usually reserved for those children that have advanced cancer with risk of spreading to the body. With the recent advancement of treatment, we strive to preserve the eye and vision. The newer targeted treatment of delivering the drug directly to the tumor in the eye viz. intra- arterial chemotherapy and intravitreal injections is very promising. The fight against this cancer becomes even more complicated when both eyes are involved. If the tumor is detected early it may be treated by freezing or by laser for tiny tumors. Treatment of retinoblastoma is an art and has to be fashioned according to case-to-case basis.
Retinoblastoma occurs due to a gene abnormality inside a developing eye, which causes the cells in an eye to multiply uncontrollably. This accumulating mass of abnormal cells forms a tumor. If left untreated, these cells can invade deeper into the eye and spread to nearby structures. Once the tumor spreads outside the eye (metastasis), it affects other areas of the body including the brain, spine and bone. In most cases, it is not clear what causes the gene abnormality that lead to retinoblastoma. In some cases, it is possible for children to inherit the gene abnormality from their parents
The tumor could be passed on from parent to child through a gene abnormality (mutation) in a gene called the ‘RB1’ gene. The mutations increase the risk of retinoblastoma and some other cancers. Only one parent needs a single mutated RB1 gene to pass the risk of retinoblastoma to their children. Children with the inherited form of retinoblastoma tend to develop the disease at an earlier age and in both eyes.
You have the possibility of passing the genetic mutation on to your children. In families with the inherited form of retinoblastoma, preventing retinoblastoma may not be possible. However, genetic testing enables families to know which children have an increased risk of retinoblastoma, so eye tests can start at an early age. This way, retinoblastoma may be diagnosed very early – when the tumor is small and a chance for a cure and preservation of vision is still possible. Genetic testing can be used to determine whether your child with retinoblastoma is at risk of other related cancers or your other children are at risk of retinoblastoma, so they can start eye exams at an early age. The doctor will need to conduct an eye exam to determine what is causing your child’s signs and symptoms. For a more detailed exam, the doctor may suggest using anesthetics to keep your child still. Scans and other tests can help the doctor determine whether retinoblastoma has grown to affect other structures around the eye. These tests may include ultrasound, computerized tomography (CT) and magnetic resonance imaging (MRI), among others.